Microsurgical procedures frequently require precision cutting and/or removing of various body tissues. For example, certain ophthalmic surgical procedures, such as vitrectomy procedures, require cutting and removing portions of the vitreous humor, a transparent jelly-like material that fills the posterior segment of the eye. The vitreous humor, or vitreous, is composed of numerous microscopic fibrils that are often attached to the retina. Therefore, cutting and removing the vitreous must be done with great care to avoid traction on the retina, the separation of the retina from the choroid, a retinal tear, or, in the worst case, cutting and removal of the retina itself. The cutting and removal of membranes may be particularly difficult in some delicate operations, such as mobile tissue management (e.g., cutting and removal of vitreous near a detached portion of the retina or a retinal tear) and vitreous base dissection.
Microsurgical procedures, such as those in the posterior segment, typically require numerous incisions to access the interior of the eye. Each additional incision may create risk for complications during the procedure and/or recovery. Various tools are inserted through the incisions for use by a user, such as a surgeon or other medical professional, while performing the procedure. For example, a portion of an infusion line may be inserted through one of the incisions. The infusion line delivers fluid to the interior of the eye to maintain intraocular pressure, thereby preventing the eye from collapsing during the surgical procedure. An illuminator, which is a distinct tool from the infusion line, may be inserted through one of the other incisions. The illuminator, such as a hand-held fiber optic probe illuminator, lights the surgical field. A third tool, a surgical device, may be inserted through yet another of the incisions. The user uses the surgical device, such as a cutting probe (i.e. vitrectomy probe), to cut and remove tissue from the eye.
A three-incision (three-port) vitrectomy procedure has multiple limitations and shortcomings. For example, the surgeon must use two hands, with an instrument in each hand. In a typical procedure, a surgeon holds an illuminator with one hand and a vitrectomy probe with the other. In addition, because there are three or more incisions in the eye, the ocular anatomy may have high levels of tissue trauma. There may be a relatively high level of ocular inflammation, and there is a higher level of potential for post-operative serious adverse events. These serious events include conjunctive bleeding, hypotony (low eye pressure) due to fluid pressure loss through wounds, endophtaltmitis (sight threatening ocular infection), choroidal re-detachment and vision loss, proliferative vitreoreinopathy (PVR), enophthalmitis (internal infection), and choroidal or retina re-detachment, among others.
Because of these risks, a three-port ocular surgery may limit the magnitude and speed of vision restoration and preservation and may ultimately decrease the chance of a satisfactory patient outcome.